<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>02_变量与常量</title>
</head>
<body>
    <script>
        //JS是一门弱类型的语言
        var a = 1;
        console.log(a);
        var b = 3.14;
        console.log(b);
        var c = true;
        c = false;
        c = '下午好！'
        console.log(c);
        var c = '我又来了！'
        console.log(c);

        let x = 1;
        //let x = 666;  //使用let声明的变量无法重复声明！
        console.log(x);

        //使用关键字const来声明常量
        const y = 1;
        console.log(y);
        //y = 2;  //常量的值不允许被修改

    </script>
</body>
</html>